dm table: simplify call to free_devices

free_devices in dm_table.c already uses list_for_each(), so we don't
need to check if the list is empty.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm-table.c

@@ -268,7 +268,6 @@ void dm_table_destroy(struct dm_table *t)
 	vfree(t->highs);
 
 	/* free the device list */
-	if (t->devices.next != &t->devices)
 	free_devices(&t->devices);
 
 	dm_free_md_mempools(t->mempools);